windows 7 slmgr.vbs tricks

I noticed a thread the other day stating about changing or hiding the product key from view. In windows 7 Press the win key + R and type slmgr.vbs and enter. Then instead of pressing OK tick the red x and you get more options. CPKY is one of those options for hiding your key. Sorry if this is a repeat of information or old news, just thought it might be helpful.